Evidence for the familial transmission of alcoholism is well-established in the empirical literature. The heritability of alcohol use disorders is high, generally around 50% (for review, see Schuckit, 2009), and figures prominently in widely cited discussions of the etiologic pathways into problematic drinking (Leonard and Blane, 1999; Sher, 1991; Tarter and Vanyukov, 1994; Zucker, 2006). Both twin and adoption studies support the heritability of alcoholism for both men and women (Heath et al., 1997; Kendler et al., 2003). Among adolescents, heritability estimates are higher for males than for females (Han et al., 1999; Rhee et al., 2003). Genetic influences may also explain greater proportions of the variance in substance use over the course of adolescence in contrast to environmental influences which appear to be more important in early adolescence (Derringer et al., 2008).
